[heap] Factor out marking state of array buffer tracker

src/heap/array-buffer-tracker.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_ARRAY_BUFFER_TRACKER_H_
 #define V8_HEAP_ARRAY_BUFFER_TRACKER_H_
 
 #include <unordered_map>
 
 #include "src/allocation.h"
 #include "src/base/platform/mutex.h"
 #include "src/globals.h"
 
 namespace v8 {
 namespace internal {
 
 class Heap;
 class JSArrayBuffer;
+class MarkingState;
 class Page;
 
 class ArrayBufferTracker : public AllStatic {
  public:
   enum ProcessingMode {
     kUpdateForwardedRemoveOthers,
     kUpdateForwardedKeepOthers,
   };
 
   // The following methods are used to track raw C++ pointers to externally
   // allocated memory used as backing store in live array buffers.
 
   // Register/unregister a new JSArrayBuffer |buffer| for tracking. Guards all
   // access to the tracker by taking the page lock for the corresponding page.
   inline static void RegisterNew(Heap* heap, JSArrayBuffer* buffer);
   inline static void Unregister(Heap* heap, JSArrayBuffer* buffer);
 
   // Frees all backing store pointers for dead JSArrayBuffers in new space.
   // Does not take any locks and can only be called during Scavenge.
   static void FreeDeadInNewSpace(Heap* heap);
 
   // Frees all backing store pointers for dead JSArrayBuffer on a given page.
   // Requires marking information to be present. Requires the page lock to be
   // taken by the caller.
-  static void FreeDead(Page* page);
+  static void FreeDead(Page* page, const MarkingState& marking_state);
 
   // Frees all remaining, live or dead, array buffers on a page. Only useful
   // during tear down.
   static void FreeAll(Page* page);
 
   // Processes all array buffers on a given page. |mode| specifies the action
   // to perform on the buffers. Returns whether the tracker is empty or not.
   static bool ProcessBuffers(Page* page, ProcessingMode mode);
 
   // Returns whether a buffer is currently tracked.
@@ skipping 10 matching lines @@
 
   enum CallbackResult { kKeepEntry, kUpdateEntry, kRemoveEntry };
   enum FreeMode { kFreeDead, kFreeAll };
 
   explicit LocalArrayBufferTracker(Heap* heap) : heap_(heap) {}
   ~LocalArrayBufferTracker();
 
   inline void Add(Key key, const Value& value);
   inline Value Remove(Key key);
 
-  // Frees up array buffers determined by |free_mode|.
-  template <FreeMode free_mode>
-  void Free();
+  // Frees up array buffers.
+  //
+  // Sample usage:
+  // Free([](HeapObject* array_buffer) {
+  //    if (should_free_internal(array_buffer)) return true;
+  //    return false;
+  // });
+  template <typename Callback>
+  void Free(Callback should_free);
 
   // Processes buffers one by one. The CallbackResult of the callback decides
   // what action to take on the buffer.
   //
   // Callback should be of type:
   //   CallbackResult fn(JSArrayBuffer* buffer, JSArrayBuffer** new_buffer);
   template <typename Callback>
   void Process(Callback callback);
 
   bool IsEmpty() { return array_buffers_.empty(); }
 
   bool IsTracked(Key key) {
     return array_buffers_.find(key) != array_buffers_.end();
   }
 
  private:
   typedef std::unordered_map<Key, Value> TrackingData;
 
   Heap* heap_;
   TrackingData array_buffers_;
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_HEAP_ARRAY_BUFFER_TRACKER_H_